Dynamo-electric machine



June 20, 1933. P. CHANDEYSSON DYNAMO ELECTRIC MACHINE Filed Aug. 3, 1931 63mm 3 1 /5225 1 Cwwoy55 0/ kg- W M 0111 1 Patented June 20, 1933 UNITED STATES PIERRE I. CHANDEYSSON, OF ST. LOUIS, MISSOURI DYNAMO-ELECTRIC MACHINE Application filed August 3, 1931.

This invention pertains to dynamo-electric machines, and more particularly to such machines of the homopolar type.

I One of the objects of this invention is to provide a machine of this type by which different voltages may be maintained in a simplified manner.

Another object is to provide a simplified construction for machines of this type.

m Another object is to provide a construction such as to improve the ventilation and accessibility of the various parts of the machine.

Another object is to provide a construction such that the machine may be manufactured at a reduced cost and with a saving of material.

Further objects will appear from the following description taken in connection with I the accompanying drawing; in which Figure 1 is a central horizontal section of a machine embodying this invention; and

Figure 2 is an end view of Fig. 1 with the driving gears removed.

In a well known type of homopolar electric generator a rotating cylindrical armature is arranged within a suitable field core structure such that a magnetic flux is caused to enter the armature radially at a certain portion thereof. This flux then traverses the armature longitudinally for a certain distance and may then be caused to leave the armature radially at a point spaced from the entrance .point of the flux. The magnetic circuit is completed outside of the armature by way of a suitable field structure. The rotation of the cylindrical armature in such a field causes the generation of an E. M. F. acting to cause a current to flow along the surface of the cylinder. Suitable brushes may then be arranged to collect this current and render it useful in an outside circuit.

In accordance with the present invention a plurality of armatures is arranged to generate current in this manner. It has been found, however, that by a suitable arrangement of the direction of flow of the magnetic flux in the field structure, such field structure 59 may be arranged to carry the flux for several Serial No. 554,688.

armatures and that a simplification and economy of construction is obtained thereby.

Referring to the drawing, 1 designates a suitable base upon which the machine may be mounted. Mounted upon but insulated from the base 1 are bearings 2 in which are journaled shafts 3 and 4 which carry cylindrical armatures 5 and 6. These armatures may be constructed of magnetic material such as iron and may be provided on their outer cylindrical surfaces each with a coating of material having a high electrical conductivity such as copper. A convenient and satisfactory manner of applying such a coating is to plate a cylinder with copper until a coating of suificlent thickness is built up. Such a coating serves not only to provide a high conductivity for carrying the generated currents, but it also provides a good contact surface for the current collecting devices.

The machine illustrated in the drawing is represented as having two armatures. These are connected by a field structure comprising a series of fiat plates arranged radially of the armatures and bridging the space therebetween. These plates are positioned at spaced points along the length of the armatures. In the drawing 7 and 8 represent a pair of field core elements placed upright in a vertical plane on the base 1, but insulated therefrom. These plates extend horizontally between the two armatures 5 and 6 and each plate has a bore adapted to accommodate each armature. Mounted Within this bore in each case is a pole shoe ring 9. Each of the rings 9 is a solid continuous ring surrounding the armature with a suitable air-gap 10 therebetween. The rings 9 are accurately fitted each in one of the bores of the plates 7 and 8. These rings are constructed of magnetic material and serve to distribute a field flux in a suitable manner along the armature.

Positioned at each end of the armatures 5 and 6 are additional field core elements 11 and 12 similar in all respects to the elements 5 7 and 8 and similarly provided with pole shoe rings 9. The core elements 11 and 12 provide magnetic return circuits to accommodate the flux carried by the elements 7 and 8. The distribution of this flux is indicated in Figure CTI ' its fieldportions provides the other unit.

2 by arrows A. It will be seen that this flux enters the armature 5 at its middle portion. It then divides, passing longitudinally toward both ends. At the ends it leaves the armature by the pole shoes 9 and passes along the core elements 11 and 12 to the armature 6. It enters the latter armature at its ends and then passes longitudinally thereof toward the middle portion, leaving the armature 6 at the middle portion and passing back along the core elements 7 and 8 to the armature 5. The approximate distribution of the flux in each of the core elements is indicated in dotted lines in Figure 2.

Field coils 13 wound in circular form so as to surround the armatures 5 and 6 are supported on the inwardly projecting portions of the pole shoe rings 9. These coils may be wound in any suitable manner, and serve to provide magnetic exitation for the entire machine. These coils may be energized from any suitable circuit or from the machine itself.

It will be noted that the construction described provides two distinct generating units, each of which is capable of generating electrical current. IVhile the field structure generally is common to both units, the armature 5 with its associated field core portions provides one unit while the armature 6 witIh t is obvious that these units may be combined in a number of different ways in accordance with the service to which they are to be applied. They may be used individually to supply separate circuits. They may be connected in series so that their voltages will be added to one another to obtain a high voltage. Also they may be connected parallel in which .case they work at the same voltage while their current capacities are added together.

their voltages are added together.

Either of these arrangements may be obtained by a very simple construction.

In the embodiment illustrated in the drawing the units are arranged in series so that It will be noted that the plates 7 and 8 are insulated from one another by suitable insulation 14. Vith the direction of flow of the field flux as indicated by the arrows A in Figure 1 I and the direction of rotation of both armatures the same as indicated by the arrows in Figure 2, electromotive forces will be generated in the two armatures in the directions indicated by the arrows B in Fig. 1. Any suitable current collecting device such as a series of brushes 15 bearing on the surface of each armature may be provided. In accordance with this invention the brushes are supported by bars 16 which are supported on the pole shoes 9. These bars may have their ends embedded in slots in the pole shoes and are not insulated therefrom, but in good electrical contact therewith. Accordingly the current collected by the brushes 15 passes to the field core elements which may thus be considered terminals for each generating unit. Considering the armature 5 and the directions of flux, rotation and E. M. F. as indicated in the drawing, the upper set of brushes of the armature 5 will be positive and the lower set negative. Taking into account the relative directions of flux and rotation in armature 6, it will be found that the lower set of brushes bearing on this armature will be positive and the upper set will be negative. As shown in the drawing the field elements 7 and 11 are continuous metallic elements extending from one armature to the other and since the current collecting devices are connected to the field elements, said elements form an electrical connection between the two generating units to connect them in series relation.

It will be noted, however, that the field core elements 8 and 12 are in electrical contact with the lower set of brushes on each armature. As there is a diiference of potential between the two armatures at this point the corresponding field core elements must be insulated from each other. Accordingly the core elements 8 corresponding to the armature 5 are separate from the core elements 8a corresponding to the armature 6 and similarly the elements 12 are separate from the elements 12a. lVhere the elements 12 and 12a meet between the two armatures they are arranged in dove-tailed relation and separated by insulation 17 as indicated in Figure 1. The purpose of the dove-tailed arrangement is to provide ample area for passage of the magnetic flux across the insulation 17. A similar construction is used to join the elements 8 and 8a.

As the core elements are in the electrical circuit of the generated E. M. F. the outside circuit to be supplied by the machine may be connected to terminals 18 fixed to the elements 12 and 12a.

In order that the armatures may rotate in the same direction there mustbe suitable driving connections between them. Accordingly each shaft 3 and 4 may be provided with suitable gears 19 which gears are connected by an idler 20 so as to cause both armatures to rotate in the same direction. Since, however, the armatures and their shafts are part of the electrical circuit the gears 19 must be insulated therefrom as by a bushing 21 or other suitable device.

In order to connect the two generating units in parallel it is only necessary to arrange the armatures to rotate in opposite directions by eliminating the idler 20 and arranging the gears 19 to mesh with each other. In this case the brushes at the same ends of both armatures will have like polarity. For instance, if the direction of rotation of the armature 6 is reverse, the upper brushes thereof will be positive and the lower negative, and

the positive ends will be connected together through the core elements 7 and 11. In this case it will be unnecessary to insulate the elements 8 and 8a, and 12 and 12a from each other. The insulation 17 may be dispensed with and each of the elements 8 and 12 made continuous across the machine. In this case also with one of the terminals 18 fixed to the core element 12 the other terminal must be fixed to the core element 11.

If it is desired to use the two generating units entirely separate from one another insulation, such as 17, may also be placed in the elements 7 and 11. In this case the generating units will be entirely insulated from one another and can be handled separately in any desired manner.

In order to arrange for mechanical assembly of th s machine the core elements are split horizontally at their middle portions as indicated at 22 in Figure 2' and may be provided with suitable lugs 23 for bolting them together after assembly. Each of the core elements is constructed in this In assembling the machine, therefore, the lower halves of the core elements are placed upon the base 1 in their proper positons. Each armature then has placed upon it the pole shoe rings 9 together with the current collecting devices 15 and the field coils 13. With these parts assembled on the armature it may then be hoisted and deposited in its bearings with the pole shoe rings properly seated in their bores in the lower halves of the core elements. When these parts have been properly placed the upper halves of the core elements are seated upon the lower halves and the two bolted together. In order to pro vide for hoisting the elements 8 and 8a and also the elements 12 and 12a each as a unit they may be bolted together at their junction as by bolts 24 suit-ably insulated from each of the elements.

The machine may be driven from any suitable source of power connected to the gears 19 or the shafts 3 or 4.

It will be seen that this invention provides a dynamo-electric machine of the homopolar type which is capable of a variety of uses and which may be adjusted as to its voltage or current output in a simple manner. It will also be noted that the radially arranged core elements are unconnected by any yokes bridging from one to another. Accordingly the space between these elements is entirely open so that the current collecting devices are easily accessible and the entire machine is well ventilated. It is also a distinct advantage of this construction that on account of the simplicity of the field core structure the amount of material required therefor is greatly reduced. Consequently the cost of construction is reduced accordingly. The fact that the current collecting devices are mounted directly on the field core structure and electrically connected thereto makes it unnecessary to provide insulation between these parts and makes it possible to use the field parts as terminals for the machine. Accordingly, a structure is produced which is simple, cheap to manufacture and very rugged.

W hile the field coils have been illustrated as wound in rings to surround the armatures, it will be noted that these may also be arranged to surround those portions in the core elements which extend between the armatures. Either of these arrangements may be used according to which one provides the cheapest or most convenient structure. It is also obvious that more than two armatures may be arranged in a unitary field structure in accordance with the principles of this invention, and connected in any desired seriesparallel relation.

lVhile this machine has been described as a unitary device it will be obvious that certain features of the invention may be useful without reference to other features or the rest of the machine. It is understood, therefore, that the employment of such individual features or combinations is contemplat ed by this invention and is within the scope of the appended claims.

It is further obvious that various changes may be made, within the scope of the appended claims, in the details of construction without departing from the spirit of this invention; it is to be understood. therefore, that this invention is not limited b0 the spe ciflc details shown and/or described.

Having thus described the invention, what is claimed is:

p 1. A dynamo-electric machine of the character described, comprising, a plurality of armatures, field exciting means, and a plurality of field core elements arranged entirely radially of said armatures and having pole shoe portions spaced axially along said armatures adapted to provide therewith a complete magnetic circuit.

2. A dynamoelectric machine of the character described, comprising, a plurality of armatures, field exciting means, and a plurality of field core elements arranged entirely radially of said armatures and having pole shoe portions axially spaced therealong adapted to provide therewith a complete magnetic circuit.

3. A dynamo-electric machine of the character described, comprising, a plurality of electrically connected together thru said frame.

5. A dynamo-electric machine of the character described, comprising, a field frame, a plurality of armatures forming therewith a plurality of generating units, said units being electrically connected in series thru said frame.

6. A dynamo-electric machine of the character described, comprising, a field frame, a plurality of armatures forming therewith plurality of generating units, said units bein g electrically connected in parallel thru said frame.

7. A dynamo-electric machine of the character described, comprising, a plurality of arinatures having their axes in parallel relation, a plurality of field core elements arranged radially of and joining said armatures to provide a magnetic circuit traversing each 01": said armatures axially and said core elements radially.

8. A dynamo-electric machine of the character described, com arising, a plurality of armatures having the'r axes in parallel relation, a field core element arranged radially of and joining said armatures at their middle portion, and field core elements arranged radially of and joining d armatures but spaced tlrerealong from said first core element and providing magnetic return circuit therefor.

9. A dynamo-electric machine of the character described, comprising, a plurality of armatures having their axes in parallel relation, a field core element arranged radially of and joining said armatures at their middle portion, field core elements arranged radially of and oining said armatures but spaced therealong from said first core element and providing a magnetic return circuit therefor. and brushes bearing on said armatures and electrically connected to said core elements.

10. A dynamo-electric machine of the character described, comprising, a plurality of rotatable armatures, and a plurality of separate field core elements extending radially of said armatures from one. to another at axially spaced points therealong and providin therewith a complete magnetic circuit.

11. A dynamo-electric machine of the character described, comprising, a plurality of rotatable armatures, and a plurality of separate field core elements extending radially of said armatures from one to another at axially spaced points therealong and providing therewith a complete magnetic circuit, said armatures forming the only magnetic connections between said field elements.

12. A dynamo-electric machine of the character described, comprising, a plurality of rotatable armatures, and a plurality of separate plate-form field core elements perforated to receive said armatures and axially spaced therealong adapted to provide therewith a complete magnetic circuit.

13. A dynamo-electric machine of the character described, comprising, a plurality of rotatable armatures having their axes in parallel relation, a field core element extending radially of and joining said armatures adjacent their middle portion, and aplurality of similar core elements extending radially of and joining said armatures at their end portions adapted to form therewith a magnetic circuit traversing said armatures axialy thereof and said core elements radially of said armatures.

14. A dynamo-electric machine of the character described, comprising, a plurality of rotatable armatures having their axes in parallel relation, a field core element extending radially of and joining said armatures adjacent their middle portion, and a plurality of similar core elements extending radially of and joining said armatures at their end portions adapted to form therewith a magnetic circuit traversing said armatures axially thereof and said core elements radially of said armaturcs, brushes bearing on said armatures, and means connecting said brushes electrically in circuit through said core elements.

In testimony whereof I allix my signature this 31st day of July, 1931.

PIERRE I. CHANDEYSSON. 

